SubThread for UIView Control

I’m continually developing original reminder’s app. I faced one issue when showing content on view. After got reminder’s data from EventStore, tried to put it as UITextView to confirm what kind reminders we can retrieve. But UITextView has error with following message.

This application is modifying the autolayout engine from a background thread, which can lead to engine corruption and weird crashes. This will cause an exception in a future release.

This was caused by multi thread processing. Some process to display reminder text into UITextFiled after get reminder data was contained in closure of function to retrieve reminder data from EventStore with identifier. Those process was called per identifier, it means in case of multi reminder list which the device has. Then each processes to modify UITextField were in subthread.  

As solution for this, I implemented “Dispatch_sync” method by referring to Grand Central Dispatch (GCD) Reference

                self.textfiled.text = "Sample text to show text from subthread."

It was success without any error. I could learn one new thing for iOS at this time.


This is my note about iOS Application development which is originally managing event data ( Calendar or Reminder) to make sure be more easy UI for me.

To get Calendar or Reminder List from iOS device, EKEventStore class is basement to access to those database. And in that data base there are some datasource. EKSource class contains data source definition like “iCloud”, “Default”, 

EKSource.title(String) SourceType Memo
Default Local  
Other ??  
Subscribed Calendar Subscribed  
iCloud CalDAV  

These definition might work for permission to read & write the event. I will keep to investigate it.



Floppy Save Icon

Just considering iOS App UI as private by referring internet. I found one topic about save icon. On smartphone app, basically autosave function should be required to make sure good usability without save icon and consciousness for saving. But some case, explicit saving by themselves is the best way to save the date since user can store historical works.

20151225saveicon I noticed almost applications have “Floppy Disk” Save icon. But Floppy Disk had been abolished for 10 years. Younger generation doesn’t know the meaning of Floppy, don’t have any experience to save data into Floppy Disk. Althought almost user can easily understand and operate to save date by clicking the Floppy Disk Icon. Needless to write, older user well remembers the sound when Floppy drive is working.

These situation makes me understand that the floppy icon doesn’t mean Floppy itself at this time, it’s function to save. I’ m not sure it’s easy to recognize the meaning of icon for younger generation who have not used Floppy Disk, but they have got the meaning without realizing. That’s very curious.

New HTTP status code 451

Finally new HTTP status code 451 was approved by IETF. RFC will be shortly delivered.

I’m wondering who can response this code. Because when user accessed the page, the censored document will be correctly passed to user, it means censorship organization or person avoids to let user know fact that be censored. Internet Provider or some service provider can response the code without presser from anyone. It must be rare case to notice the fact.

According to some internet article about this, there were so many type of the opinion for agree or disagree.  Code space is limited, it’s good to collect the fact that there are some censorship on internet and so on.

In near future, statistic report about this will be revealed by lab and internet research company. I’m looking forward to see the result. 

Good reference for beginner of iOS App developer

From beginning of this year, I have been planning to develop iOS App to learn Swift and Xcode development. As first step, started with learning some UI design concept for iOS and making mock. There are many document or guideline offered by Apple.  And Adobe provides many tool to make mock for Smartphone Apple. 

I would like to recommend some documents and services for the beginner of developer like me. and if i will find more good one, let me update here or post new one.

Site Title Memo
Apple iOS Human Interface Guidelines. Basic Document
Apple WWDC Video Official and biggest MacOSX and iOS developer conference by Apple.
Adobe Adobe Comp Mock Application for not only for SmartDevice, also Web & Publishing. Easy to share the mock with Desktop Adobe Creative Suite like Photoshop and Illustrator.  
A Map of the Unexplored Project iOS Fonts Available Font list on iOS Application.